Die-stock.



J. C. FLETCHER.

'DIE STOCK.

APPLICAUON FILED JULY lo, 1913.

Patented Apr. 27, 1915.

JOSEPH C. FLETCHER, OF CHICAGO, ILLI NCIS, ASSIGNOR 'IO THE NYE TOOL AND MACHINE WORKS, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS,

nin-STOCK. A

Mamet..

specication of Letters Patent.

' Patented Apr. 2*?, 1915..v

Application filed July 10, 1913. Serial No. 778,274.

To all whom t may concern:

Be it known that I, JOSEPH C. FLETCHER, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Die-Stocks, of which the following is a specification.

` My invention relates to die stocks for cutting thread, and the object of the invention is to'provide simple andveflioient means in a device of this character for controlling the thread cutting dies or chasers.

My Objectis obtained by the construction illustrated in the accompanying drawings in which- Figure 1 is a longitudinal section of the device taken on the line 1 1 of Fig. 2. Fig. 2 is an elevation partly in section taken on the line 2-2 Fig. l. Fig. 3 is aperspective of one of the controlling levers and Fig. 1 is a perspective of the ring or collar which controls the levers.

Similar numerals refer to similar parts throughout the several views.

A. stock body 1 is provided with handles 2 in the usual manner. Extending fromthe stock body is a tubular extension 3 which is exteriorly threaded to engage with corresponding threads upon the interior of the work holder or leader bushing 4:. Said leader bushing is secured to the pipe or rod 5 (which constitutes the work) by set screws 6 or other suitable device. The thread cutting dies 7 are arranged to slide radially within the stock body so as to produce a taper thread upon the work. These dies are recedingly held to the work by levers 8 fulcrumed upon pins 9 mounted inthe stock body. In the preferred construction the pins 9 are mounted in extensions 10 projecting from the front of the stock body and apertures l1 are formed in the stock body for accommodating the controlling levers which extend back toward theleader bushing. As a result of this design, the stock body forms a housing for a considerable portion of the levers and protects them from damage which might arise from contact with external objects.

The controlling levers back up the dies and are provided with bosses 12 which contact the dies at the outer ends thereof and are rounded to permit the levers to seat firmly upon the dies throughout all the various angles assumed by the levers.

The levers are controlled at the free ends byanti-friction rollers 13 mounted on pins 14 secured to arms 15 extending from the controlling ring or collar 1G. lThe pins 14 are located at a greater distance from the axis of the device than the pins 9 and consequently, the controlling levers when in action lie obliquely with reference to the axis of rotation of the device. Notches 8a are formed in the outer working edges of the levers for accommodating the rollers 13 and permitting said levers to recede. rapidly when the thread cutting process is finished and the dies are to be withdrawn from oontact with the'work.

Ring 16 is rotatable upon the leader busliing, being held laterally between a shoulder 17 formed on the leader bushing and a ring nut 18 whichscrews upon the forward end of the leader bushing. Ring 16 is forced to rotate in unison with the stock body, the preferred agency being the pins 19 which are rigidly fastened to the stock body and extend rearwardly through apertures 20 formed in suitable lugs 21 formed upon the ring.

The parts are so proportioned and arranged that when the dies are at the beginning of the cut-that is, at the outer end of the workthe anti-friction rollers V13 will engage the working edges of the levers at or near the free ends of said levers. As a result, said levers will at this time lie'most nearly parallel with the axis of rotation and this will hold the dies at their innermost position. Starting with this initial position when the stock body is rotated, the dies 7, levers 8 and controlling ring 16 will rotate with it. As the controlling ring is laterally fixed it will not change its position lengthwise of the axis of rotation, but the stock body, dies and levers will progress in an axial direction due to the coaction of the threaded extension 3 with the internal threads of the leader bushing, consequently, during the thread cutting operation the pins 9 will gradually approach the pins 14, and as said pins are at different distances from the axis of rotation, the controlling levers will gradually increase their obliquity and permit the dies to gradually .recede and thus produce; a taper to the.VV

thread.` When the operation hasproceededj Y :far enoughv Vto finish the thread upon the work, the anti-friction rollers llrea'ch the notches Safformed in the Working edges of the levers-'and permitthe levers to Vswing outwardly sufficiently toy release the dies from the Work and'permit them to be disengaged from `.thethread they have cut'and thus allowthe .diesfand diestock to be rapidly removed fromthe Work.

YI claim:

V1. In a i thread ,cutting device, va stock body, a die movable toward and from the Work, a leaderbushing screwing upon saidV stock body and VAadapted to be fastened to thevwork, a rotatable ring having a fixed position lengthwise ofthe axis of rotation, anda lever operatively engaging said die and being controlled jointly by the ring and stoclrl body, saidlever being oblique to the axis of thestock b'ody and being pivoted to onefof theY two' last mentioned parts and al-V of'rotation and a fixedposition lengthwiseV Ways engaging the other of'said parts at a point having a-ixeddistance VJfrom the axis ofthe axis of rotation, said lever being con-. trolled from points on opposite-sides of the vpoint of' action of the lever upon the die.,

2,In a thread cutting device, a stock v body, a Adie movable toward and from the Work, a -leader bushing screwing `upon the stock body and adapted to be-fastened to the Work, a rotatable ring having a fixed position lengthwise of the axis of rotation,

and a lever oblique to the axis of the stock body, said lever being pivoted to said stock bodyand being acted upon by said ring at a point whose. distance vfrom the axis of the stock body is constant, said lever acting I upon said dieV at a point between its pivot and the point Where it is acted upon by the ring.

3. In adie stock, a stock body, a lever fulcrumed on said stock body, and having a Working edge, said lever being oblique to the axis of the stock bodya radially movable vdie held to its YWork by said lever, a

non-travelingrrotatable ring acting upon the Workingedge orv said lever at a point having a xed distance from the axis of the stock body, the lever fulcrum and the point of action'of the ring upon the lever being on opposite sides of the die, and a Work holder for causing the stock body With its leverv fulcrum and die to travel toward said rin-g as the stock body yis rotated in a 'direction -to cut a thread on the Work.

. t. In a die' stock, a'stock body, a die radially slidable therein, a Work holder for causing the stock body to travelV axially when rotated, a` lever holding the die to its Work, said lever being oblique to the axis Working edge, a non-traveling rotatable ring acting` upon the outer Working edge .of the lever at a point Whose distance from the axis of the stock body is constant, said lever being pivoted to the stock body at a point on the'opposite side of the die from the point Where said lever is actedupon by said ring, and the point of action of the ring upon the lever being farthest from the lever pivot at the beginning of the cut,

tion roller mounted in said tiing and acting upon the Working edge of vsaid lever, the

lever fulcrum andV the anti-friction roller engaging the lever on opposite sides of the die, and a Work holderfor causing the stock body to travel toward said ring as the stock body is rotated in a direction to cut a thread on the Work.

6. In a die stock, a stock body, a die radially slidable therein, a leader bushing screwing `on said stock body and adapted to be fastened tothe Work, a lever pivoted to tliestoclz body and adapted to back up the die, said lever having a working edge, an axially fixed rotatable ring,k and a projection on said ring adapted to travel along the working edge of said lever as the stock body progresses axially, said lever having a notch in itsworking edge for quickly releasing the die when the thread is finished.

l 7. In a die stock, a stock body, a die radially slidable therein, a Work holder for causing the stock body to travel axially when rotated, a lever pivoted to the stock body, a rounded boss on said lever adapted to contact the outer end of the die, an axially fixed rotatable ring mounted on the Work holder, and means on the ring adapted to travel along the outer edge of the lever as the die progresses axially, said boss being located betvveen the lever pivot andY the point of contact of the lever with the said means on the ring.

8. In combination in a device of the class described, a stock body, dies radially slidable therein, a Work holder for causing the stock body to travel axially When rotated, levers oblique to the axis of the stock body and backing up the dies and pivoted to the stock body, a ring rotatable upon the Work holder and suitably held against axial movement, said levers passing through said ring, and anti-friction rollers carried by said ring and adapted to engage the outer edges of said levers for holding ythe latter at various angles of Obliquity depending upon the pomemo@l y Sition of the stock body longitudinally of the aXis of rotation, the lever pivots being near the outer end of the stock body and near the outer end of the levers, and the ring being near the inner end of the levers and the dies being located between the ends of the levers.

In witness whereof, I have hereunto subscribed my name inthe presence of two witnesses. A y

JOSEPH C. FLETCHER. Witnesses:

HOWARD Mi COX, MAX S. ROSENZWEIG.

Copies of this patent may ne obtained for ve cents each, by addressing the Commissioner of Patents,

Washington, D; C. 

